diff --git a/addonsu/mount-system.sh b/addonsu/mount-system.sh
index 2e209fb2..5886f153 100644
--- a/addonsu/mount-system.sh
+++ b/addonsu/mount-system.sh
@@ -10,4 +10,19 @@ if [ -n "$block" ] && mount $block /system; then
     exit 0
 fi
 
+# Modern devices use /system as root ("/")
+system_as_root=`getprop ro.build.system_root_image`
+if [ "$system_as_root" == "true" ]; then
+  active_slot=`getprop ro.boot.slot_suffix`
+  if [ ! -z "$active_slot" ]; then
+    block=/dev/block/bootdevice/by-name/system$active_slot
+  else
+    block=/dev/block/bootdevice/by-name/system
+  fi
+  mkdir -p /system_root
+  if mount -o rw $block /system_root && mount /system_root/system /system; then
+    exit 0
+  fi
+fi
+
 exit 1
diff --git a/addonsu/unmount-system.sh b/addonsu/unmount-system.sh
new file mode 100644
index 00000000..60c5e18f
--- /dev/null
+++ b/addonsu/unmount-system.sh
@@ -0,0 +1,15 @@
+#!/sbin/sh
+
+# Modern devices use /system as root ("/")
+system_as_root=`getprop ro.build.system_root_image`
+if [ "$system_as_root" == "true" ]; then
+  if umount /system && umount /system_root; then
+    exit 0
+  fi
+fi
+
+if umount /system; then
+    exit 0
+fi
+
+exit 1
diff --git a/addonsu/updater-script-install b/addonsu/updater-script-install
index 60c167e4..c807739f 100644
--- a/addonsu/updater-script-install
+++ b/addonsu/updater-script-install
@@ -1,23 +1,17 @@
 ui_print("Installing su addon...");
 ifelse(is_mounted("/system"), unmount("/system"));
 package_extract_file("mount-system.sh", "/tmp/mount-system.sh");
+package_extract_file("unmount-system.sh", "/tmp/unmount-system.sh");
 set_metadata("/tmp/mount-system.sh", "uid", 0, "gid", 0, "mode", 0755);
+set_metadata("/tmp/unmount-system.sh", "uid", 0, "gid", 0, "mode", 0755);
 run_program("/tmp/mount-system.sh") == 0 || abort("Could not mount /system");
 
-if getprop("ro.build.system_root_image") != "true" then
-  package_extract_dir("system", "/system");
-  set_metadata("/system/addon.d/51-addonsu.sh", "uid", 0, "gid", 0, "mode", 0755, "selabel", "u:object_r:system_file:s0");
-  set_metadata("/system/etc/init/superuser.rc", "uid", 0, "gid", 0, "mode", 0644, "selabel", "u:object_r:system_file:s0");
-  set_metadata("/system/xbin/su", "uid", 0, "gid", 2000, "mode", 0755, "selabel", "u:object_r:su_exec:s0");
-  symlink("/system/xbin/su", "/system/bin/su");
-else
-  package_extract_dir("system", "/system/system");
-  set_metadata("/system/system/addon.d/51-addonsu.sh", "uid", 0, "gid", 0, "mode", 0755, "selabel", "u:object_r:system_file:s0");
-  set_metadata("/system/system/etc/init/superuser.rc", "uid", 0, "gid", 0, "mode", 0644, "selabel", "u:object_r:system_file:s0");
-  set_metadata("/system/system/xbin/su", "uid", 0, "gid", 2000, "mode", 0755, "selabel", "u:object_r:su_exec:s0");
-  symlink("/system/xbin/su", "/system/system/bin/su");
-endif;
+package_extract_dir("system", "/system");
+set_metadata("/system/addon.d/51-addonsu.sh", "uid", 0, "gid", 0, "mode", 0755, "selabel", "u:object_r:system_file:s0");
+set_metadata("/system/etc/init/superuser.rc", "uid", 0, "gid", 0, "mode", 0644, "selabel", "u:object_r:system_file:s0");
+set_metadata("/system/xbin/su", "uid", 0, "gid", 2000, "mode", 0755, "selabel", "u:object_r:su_exec:s0");
+symlink("/system/xbin/su", "/system/bin/su");
 
-unmount("/system");
+run_program("/tmp/unmount-system.sh") == 0 || ui_print("Could not unmount /system");
 ui_print("Done");
 set_progress(1.000000);
diff --git a/addonsu/updater-script-remove b/addonsu/updater-script-remove
index b89b572d..ba4fcaa8 100644
--- a/addonsu/updater-script-remove
+++ b/addonsu/updater-script-remove
@@ -1,21 +1,16 @@
 ui_print("Removing su addon...");
 ifelse(is_mounted("/system"), unmount("/system"));
 package_extract_file("mount-system.sh", "/tmp/mount-system.sh");
+package_extract_file("unmount-system.sh", "/tmp/unmount-system.sh");
 set_metadata("/tmp/mount-system.sh", "uid", 0, "gid", 0, "mode", 0755);
+set_metadata("/tmp/unmount-system.sh", "uid", 0, "gid", 0, "mode", 0755);
 run_program("/tmp/mount-system.sh") == 0 || abort("Could not mount /system");
 
-if getprop("ro.build.system_root_image") != "true" then
-  delete("/system/addon.d/51-addonsu.sh");
-  delete("/system/bin/su");
-  delete("/system/etc/init/superuser.rc");
-  delete("/system/xbin/su");
-else
-  delete("/system/system/addon.d/51-addonsu.sh");
-  delete("/system/system/bin/su");
-  delete("/system/system/etc/init/superuser.rc");
-  delete("/system/system/xbin/su");
-endif;
+delete("/system/addon.d/51-addonsu.sh");
+delete("/system/bin/su");
+delete("/system/etc/init/superuser.rc");
+delete("/system/xbin/su");
 
-unmount("/system");
+run_program("/tmp/unmount-system.sh") == 0 || ui_print("Could not unmount /system");
 ui_print("Done");
 set_progress(1.000000);
diff --git a/build/tasks/addonsu.mk b/build/tasks/addonsu.mk
index 9b367c11..8f963872 100644
--- a/build/tasks/addonsu.mk
+++ b/build/tasks/addonsu.mk
@@ -15,6 +15,7 @@ $(ADDONSU_INSTALL_TARGET): $(ALL_MODULES.updater.BUILT) \
 	$(hide) cp $(ALL_MODULES.updater.BUILT) $(ADDONSU_INSTALL_OUT)/META-INF/com/google/android/update-binary
 	$(hide) cp $(ADDONSU_PREBUILTS_PATH)/51-addonsu.sh $(ADDONSU_INSTALL_OUT)/system/addon.d/
 	$(hide) cp $(ADDONSU_PREBUILTS_PATH)/mount-system.sh $(ADDONSU_INSTALL_OUT)/
+	$(hide) cp $(ADDONSU_PREBUILTS_PATH)/unmount-system.sh $(ADDONSU_INSTALL_OUT)/
 	$(hide) cp $(ADDONSU_PREBUILTS_PATH)/updater-script-install $(ADDONSU_INSTALL_OUT)/META-INF/com/google/android/updater-script
 	$(hide) (cd $(ADDONSU_INSTALL_OUT) && zip -qr $@ *)
 
@@ -31,6 +32,7 @@ $(ADDONSU_REMOVE_TARGET): $(ALL_MODULES.updater.BUILT)
 	$(hide) mkdir -p $(ADDONSU_REMOVE_OUT)/META-INF/com/google/android/
 	$(hide) cp $(ALL_MODULES.updater.BUILT) $(ADDONSU_REMOVE_OUT)/META-INF/com/google/android/update-binary
 	$(hide) cp $(ADDONSU_PREBUILTS_PATH)/mount-system.sh $(ADDONSU_REMOVE_OUT)/
+	$(hide) cp $(ADDONSU_PREBUILTS_PATH)/unmount-system.sh $(ADDONSU_REMOVE_OUT)/
 	$(hide) cp $(ADDONSU_PREBUILTS_PATH)/updater-script-remove $(ADDONSU_REMOVE_OUT)/META-INF/com/google/android/updater-script
 	$(hide) (cd $(ADDONSU_REMOVE_OUT) && zip -qr $@ *)